Sound reproducer



-W. Y. CANNON SOUND REPRODUCER Aug. 30, 193s.

Filed Sept. 16, 1935 2 Sheets-Sheet 1 3mm Y(;lfud.5. Cannon.

Aug. 30, 1938.

W. Y. CANNON SOUND REPRODUCER Filed Sept. 16, 1935 2 Sheets-Sheet 2 Gum/am,

Patented Aug. 30, 1938 UNITED STATES PATENT OFFICE J SOUND nnrnonoonn Wilford Y. Cllm0n, Salt Lake out. Utah Application September 1c, 1935, Serial No. 40,147

1 cum; (or 179-116) My invention relates to sound reproducers and more particularly to the type known as ear phones and has for its object to' provide a new and emcient double diaphragm ear phone which will be more efficient, give better voice and sound reproduction and greater selectivity than those now on the open market.

A further object is to provide a new type'ear phone which will use light weight rubber or fabric tubes leading to the ears of the user and which will have the reproducing unit mounted to rest upon a table or on the chest of the user, enabling a person to use ear phones in telephony, telegraphy, radio, and kindred uses without the heavy phones being carried on the head and weighing so heavy on the ears of the user.

A still further object is to provide an economical reproducing element having inexpensive parts, but giving greater field of reproduction and using two diaphragms mounted to a single armature and giving .ofl sound in both directions from the unit and with this unit, the extra ear phone is eliminated and its accompanying parts arenotused and also the head piece and support of the usual head set is eliminated.

A still further object is to provide a better method of securing the lead in wires to the reproducer providing a unit from which the lead in wires may be pulled out but it they are pulled violently out they will not damage the unit or dislodge or break any of the connecting wires of the voice coil.

A still further object is to provide a double diaphragm phone with spacer between so that by means of tubing connections to the ears, one armature, voice coil, and magnet will serve the purpose of the two new used, with the one unit giving reception to both ears and eliminate much static and outside interference found with double ear phones commonly used in head sets.

A still further object is to provide a new and efficient mounting for the diaphragm giving fuller action and greater sensitivity to the unit.

These objects I accomplish with the device l1- lustrated in the accompanying drawings in which similar numerals and letters of reference indicate like parts throughout the several views and as described in the specification forming a part of this application and pointed out in the appended claim.

In the drawings in which I have shown my device.

Figure 1 is a vertical diametrical section of one of my reproducing units.

Figure 2 is a face view of one 01' the units with one side removed and with one diaphragm left of! to show the interior mounting of the device.

Figure 3 is a view oi the double diaphragm and connecting pin.

Figure 6 is a plan view of the voice coil spool.

Figure 7 is an end view of Figure 6.

Figure 8 is a diametrical section of a modified reproducing unit showing the use of a. flat magnetfor an inexpensive unit.

Figure 9 is a section on line. 9-9 of Figure 8.

Figure 10 is a vertical section of the same single straight magnet shown in use in an ear phone with only-one diaphragm and showing the same new diaphragm mounting.

Figure 11 is a side elevation of Figure 9.

Figure 12 is a diagrammatic view showing the use of the ear plugs used on the tubing to connectthe speaker unit with the ears.

In the drawings I have shown the reproducing unit as A, having end members or caps B and C formed with medial holes I therethrough into which hollow, stems 2 are secured. The end caps B and C and the hollow stems are alike. The end caps B and C are flanged and the flange is internally threaded to be screwed onto a joining spacer cylinder 3. A step outis formed on the inner face of each cap and the diaphragms G and I mounted in these steps being formed preferably of equal diameters, and first an inner ring 8 is placed within the step at the back side thereof and then the diaphragm is placed in the step and outside this another snap spring ring 9 is snapped into place holding the diaphragm mounted therebetween giving a full amount of flexibility to the diaphragm. To the cap B I then secure my horse shoe magnet ill by suitable clamps or brackets II and the ends l2 and i3 of the magnet are provided with pole pieces l4 and I5 respectively. These pole pieces are U-shaped and carry the voice spool and coil C therebetween. The coil C is provided with a core I! in which the armature i8 is pivotally mounted by inserting pointed pivot pins Illa through the sides of the core I! with the points of the pins inserted into conical sockets IS in the sides of the armature l8. The side 20 of the coilis provided with a cylindrical boss 2| near the outer perimeter thereof adjacent one end and a like boss Zia near the core and the wire 22 oi the coil is passed through these bosses and secured thereto by suitable means to more securely hold the wires of the coil from loosening or leakage. The wire 22 is then connected at each free end to screws 23 which screws are inserted into threaded sockets. Two sockets 2! are bored into the side of cap B and the plugs 2' of the connecting lead in wires 21 are placed in the socket 25 and the screw 23 screwed down onto the plugs to make the contact between the voice coil and the lead in wires and with this connection the tension or stress from the lead in wires is eliminated from the coil or coil wire.

In the modified form of the unit shown in Figure 8 the ends of the unit are shown as 30 and ll with the end II the end to which my flat magnet 33 is secured by a cap screw 34. This magnet has bifurcated pole pieces I! secured onto the end 31 by the same cap screw 34 and this pole piece is made of a flat strip of metal with the ends bent with one end secured to the magnet and the other bifurcated end "a secured to the U-shaped pole piece 38. The other pole 39 is U- shaped and like the pole piece ll and between them they hold the voice coil 40 on the spool ll. Each of the ends 3|! and II are provided with a step cut 42 similar to the step cut shown at 5 in Figure 4 and the two diaphragms N and 45 are carried therein held in place by the rings 48 and 41. The pin It then connects the two diaphragms l4 and together and to the armature 4 8, with one end of the pin passing between the legs or the bifurcated pole piece 8! as shown in Figures 8 and 9.

In Figure 10 the use of a single flat magnet is shown with the device made as an ear phone tor the type now in use with only one diaphragm and the pin connecting the diaphragm with the armature and not extended out. This view also 5 shows my mounting of a single diaphragm in the usual type oi ear phone improving the reproduction of this type oi instrument.

In Figure 12 the general assembly 0! the preierred type or unit A is shown with tubing E and F connecting the two stems 2 with the ear plugs G to transmit the sound to the ear in a manner similar to the stethoscope, used by physicians.

Having thus described my invention I desire to is extended at an angle from one end of said magnet 23 to a point spaced irom the other end of said magnet; a U-shaped pole piece carried on said bar spaced to coincide with the sides of the first mentioned pole piece; a voice coil mounted between said pole pieces; an armature in said coil: 36

spaced apart diaphragms mounted one in each cap; and a single connecting pin connecting the two diaphragms and the armature.

WILFORD Y. CANNON. a5 

